Viscosity control is essential in many of today's manufacturing and printing processes. Viscosity is the measure of the resistance of a fluid to deformation by either shear stress or extensional stress, but is commonly perceived as the “thickness” or resistance to flow of a fluid. Viscosity can be an important quality of a finished product (e.g., a lubricant, paint, or ink) or can affect a finished product (e.g., printed material). Perhaps more importantly, an inappropriate viscosity can adversely affect modern industrial equipment. For example, if the viscosity of printing ink falls outside of an acceptable viscosity ranges, not only is print quality affected, but the printing press can also become fouled.
Various viscometers have been proposed over past century in which measuring equipment directly contacts the fluid to be measured. Such equipment can be problematic for several reasons. First, the moving parts are difficult and time consuming to clean. This adds time effort to cleanings of manufacturing equipment either required periodically or when a manufacturing line is changed from one product to another. Second, the moving parts present additional risk of mechanical failure.
Accordingly, it would be desirable to provide a viscometer with no moving parts that is both durable and easy to clean.